Stabilized hydrogen peroxide solutions used for water disinfection, such as HUWA-SAN™ owned by Roam Chemie NV of Houthalen, Belgium, and SANOSIL™ owned by Sanosil Ltd. of Hombrechtikon, Switzerland are known in the art. Such hydrogen peroxide (H2O2) solutions are proprietary and are stabilized by silver ions or silver colloid in minute concentrations. Other stabilized hydrogen peroxide solutions are stabilized by alcohols, acids or other compounds. Depending on the solution, the stabilizer prevents the hydrogen peroxide from oxidizing too quickly when it contacts water, thereby allowing the solution to mix with the water before binding to and disinfecting undesirable microorganisms and chemicals.
Various apparatuses exist to measure the concentration of hydrogen peroxide in water including with chemiluminescent, fluorometric, amperometric and colorimetric sensors. The prior art sensors and detection systems were built to measure hydrogen peroxide concentration thresholds in swimming pool water treatment systems where regulations allow maximum levels not to exceed, for example, 150 mg/L (150 ppm), and typical operating concentrations are between 50-100 ppm. Other regulations have standards in the same order of magnitude.
In drinking water regulation, however, the acceptable concentration thresholds are much lower, often in the order of under 10 ppm. For example, in Ontario, Canada, operating concentrations for drinking water are between 2-8 ppm. Existing detection methods are inadequate to quickly measure the concentration of hydrogen peroxide in water at such low levels at an accuracy better than ±3 ppm.
There is a need for a measurement apparatus and method to quickly detect low concentrations of hydrogen peroxide in water, including drinking water, in the order of 10.0 ppm or less and to an accuracy of 0.1 ppm. Such techniques must not be affected by pH, temperature or water composition.